According to the official announcement by Tumblr any user can message any other user by default. Settings can be changed to block any person that you’re not following. So potentially your child can be messaged by anyone on Tumblr. I’m not saying that your child will be approached by every predator on Tumblr however, it is one more avenue that they’ve been given.

The messaging service will be available on both desktop (pcs and laptops) and mobile (phone and tablet) platforms. So all anyone needs to access this service is a device and a wifi connection. If you’re a parent this is one more instant messaging app that you need to be aware of in order to better protect your kids.